In previous fully concealed hinge designs, whether these hinges were of the 90 degree opening type or of the type having a full opening angle of 165 degrees or more, there has been the necessity of machining the door to receive the hinge. This machining process involved either cutting a slot near the edge of the door or boring a rather large diameter, deep hole. These hinges were known as the "32 millimeter system" or the European type of cabinet hinge. In addition to the large hole being required in the door, this type of installation also required three different thicknesses of mounting plates to accommodate the different amount of door overlay relative to the cabinet. There are about four different types of European hinges for the 90 degree to 120 degree hinges. Also, there are special European-type hinges required for doors that are 7/8 inch to one and one-quarter inches thick.
Patents disclosing the European type of fully concealed hinge and illustrating the points mentioned above, include U.S. Pat. No. 3,626,548 to H. Grunert; U.S. Pat. No. 3,863,292 to H. Grunert, et al.; and U.S. Pat. No. 3,978,549 to T. Vitt. Attention is also directed to N. H. Nyquest U.S. Pat. No. 3,038,196, granted June 12, 1962, which shows an intermediate, slot mounted plate, and associated linkage, which patent was cited in the parent case.
A principal object of the present invention is to provide a fully concealed hinge which will avoid the problems and shortcomings of the prior art hinges as outlined hereinabove.